Snap ring tool



April 17, 1956 J, KRQDEL 2,741,829

SNAP RING TOOL Filed May 2o, 1952 4 [Wil/11111111111111111111 IN VENTOR.

United States Patent O SNAP RING TOOL Leander J'. Krodel, Westmont,lll., assigner to General Motors Corporation, Detroit, Mich., acorporation oi Delaware Application May 20, 1952, Serial No. 288,872.

4 ClBimS. (Cl. 29229) This invention relates generally to assembly anddisassembly tools and more particularly to sliding pincer tools used toapply and remove open ended snap retaining rings.

In the various assemblies of manufacture the use of snap rings hasbecome very extensive and today one may find snap rings in a variety ofsizes and shapes. In fact, the only apparent limiting factor on evenfurther increases in the use of such rings appears to be in the problemof applying these rings to their assemblies. Naturally, as larger sizesnap rings having stronger retaining characteristics are used, greaterforces are needed to contract them. These greater forces usually meanincreasing the size of the tool which applies and removes the snaprings. It readily can be seen that the maximum size snap ring that maybe used will depend almost wholly on the size tool necessary to applythat ring. In other words, if the tool is so large that its operatorfinds it awkward and unwieldly to handle, it becomes impractical to usethat tool and the size of snap ring it was made to handle.

Related to the above problem, a further ditliculty experienced byoperators of snap ring tools has been maintaining the snap ringcompressed for the period between compression and application. ln otherwords while the operator may have sulicient strength to compress thering a correct amount, he does not possess enough strength to maintainthe ring in its compressed condition until it can be applied. In anattempt to circumvent this diliculty, certain tools have been providedwith locking devices which must be set manually by the operator afterthe ring has been compressed. However, if the operator is applyingmaximum force to the snap ring through the use of both hands on thetool, obviously any attempt on his part to set manually a locking devicewill result ultimately in no application of the ring.

It, therefore, becomes an object of this invention to provide a snapring tool which due to its unique construction will compress snap ringsof much greater size and strength than other tools of comparable weightand s1ze.

It is another object of this invention to provide a snap ring toolhaving a unique lock which is automatically applied when the snap ringis compressed a correct amount and which maintains the ring compressedduring the period between the culmination of the act of compression andapplication.

It is a further object of this invention to provide a tool having aminimum of parts which is simple to operate and inexpensive tomanufacture.

In the drawings:

Figure l is a front view of the new improved tool with one side removedshowing ring engaging fingers in both an extended and retractedposition.

Figure 2 is a section taken along the line 2 2 of Figure 1.

Figure 3 is a partial section taken along the line 3 3 rice showing thedetails of the thumb knob used to extend and retract the engaginglingers.

Figure 4 is a section taken along the line 4 4 and shows the lockingmeans for holding the snap ring in its compressed condition.

Referring to Figure 1, the snap ring tool is shown generally by 2. Thesnap ring tool comprises a housing 4 which includes two sides 6separated at one end by spacers 8 and at the other end by the spacingportion 10 of a handle 12. The two sides 6, the spacers 8 and the handle12 with the spacing portion 10, are all fastened together by peenedrivets 14. A spreader pin 16 is located at one end of the housing 4 andextends between the sides 6.

Located within the housing 4 are a pair of pivotally connected lingers18 and 19. These fingers 18 and 19 extend outside the housing at one endthereof on opposite sides of the spreader pin 16. On the end of eachfinger, extending outside of the housing 4, are located work engagingpins 20. These work engaging pins 20 are adapted to lit in aperturesprovided in the snap ling itself.

Referring now to Figures l, 2 and 3, the sliding and pivoting assemblyfor operating the tool is shown. This assembly includes a bushing 22adapted to slide in longitudinal slots 24 located in each side plate 6and a fastening pin 26 contained within the bushing 22, which maintainsserrated thumb knobs 28 on opposite sides of the housing 4. The bushing22 also serves as the pivotal connection for the ngers 1S and 19.

The locking mechanism of the tool is more clearly illustrated in Figuresl and 4. Figure l shows the slide bars 3 having inner surfaces 30extending longitudinally along the tool. Adapted to mate with thesurfaces on the slide bar 8 are surfaces 32 also extendinglongitudinally of the tool when the fingers 1S and 19 are in theretracted position. The forces created by the compressed retaining ringand obtained between these two sets of surfaces serve to hold the toolin its retracted position and the retaining ring in its compressedcondition.

The operation of the tool is as follows: The thumb knobs 28 are pushedalong the slots 24 to the bottom position therein. This will positionthe work engaging pins 29 as shown by the dotted lines in Figure l.These work engaging pins are placed in the retaining ring apertures withthe retaining ring in its uncompressed condition. The thumb knobs 28 arethen drawn upwardly along the slots 24 or else the handle i2 is pusheddownwardly toward the retaining ring so that the thumb knobs 28 moveupward along the slots 24 to the topmost position. At this point thesurfaces 3d and 32 engage with each other to lock the tool with theretaining ring in its compressed condition. The ring then may beinserted in an internal groove at which time the thumb knobs are pusheddownwardly again, releasing the retaining ring into its retaininggroove.

l claim:

l. A tool for expanding and contracting retaining rings comprising anelongated housing having oppositely disposed slots runninglongitudinally therealong, a pair of parallel pins extending laterallythrough said housing and spaced longitudinally along said housing fromeach other, one of said pins riding in said slots and pivotallyconnecting a pair of rigid fingers located within said housing, saidngers having work engaging ends extending without said housing onopposite sides of the other of said pins, and means provided outside ofsaid housing and on the one of said pins for moving the one of said pinsand said connected fingers longitudinally with respect to said housingto retracted and extended positions, and means for retaining saidfingers in said retracted position when compressing a retaining ringbetween said work engaging ends, said means including a pair ofoppositely dissurfaces normal to the direction of forces exerted onVsaid ends by said retaining ring compressed therebetween, and surfaceson said lingers parallel rto the surfaces on said spacers and engageabletherewith when said ngers are in said retracted position. Y

2. A tool for contracting and expanding Vretaining rings comprising ahousing having oppositely disposed slots, a pair of parallel pinsextending laterally through said housing and spaced from each other,Vone of said pins riding in saidV slots and pivotally connecting a pairof rigid fingers located within said housing, said lingers having workengaging ends extending Without said housing on opposite sides of theother of said pins, means for moving said fingers with respect to saidhousing to extended and retracted positions, Vand means for restrainingmovement of said fingers with respect to said housing when in saidretracted position, said last means'including a surface in said housingnormal to the direction of the Y forces exerted between said ends byretaining rings engageable therebetween, and an adjacent surface on oneof said ngers parallel to the surface on said housing and engageabletherewith when said fingers are in said retracted position.

3. A tool for expanding and contracting retaining rings and the likecomprising a member, a pair of intersecting rigid fingers, said fingersbeing supported by said member and connected together where theyintersect bymeans movable relative to said member, a finger spreadingelement on said member spaced from said means, said iingers extendingpast and engageable with said element on opposite sides thereof, lingercamming means on said member spaced from said means and engageable withsaid ngers to reduce the amount of spread betweensaid lingers, saidfingers having work Vengaging portions operable to expand and contractretaining rings and the like in response to movement of said means indierent directions thereby causing said y iingers to move past saidelement and said linger camming means, and parallel engageable surfaceson said finger cammingmeans and said member for restraining movement ofsaid ngers relative to said member otherwise caused by forces exertedbetween said lingers and said iinger camming means by retaining ringsand the like compressed between said work engaging portions, saidsurfaces being normal to the forces exerted therebetween by retainingringsV andV the like compressed between 'said work engaging portions.

4. A tool for expanding and contracting retaining rings and the likecomprising an elongated housing having oppositely disposed slots runninglongitudinally therealong, a handle on one end of said housing, a pinextending laterally through said housing and guidable in said slots, apair of intersecting fingers located within said housing and pivotallyconnected together at their intersection by said pin, a linger spreadingelement on said member ex tending laterally through said housing andspacedlongitudinally along said housing from said slots, said fingersdefining a variable angle therebetween intermediate said pin and saidelement, said fingers extending past and engageable with said element onopposite sides thereof, said fingers having retaining ring engagingportions extending out yof said housing on opposite sides of said fingerspreading element, a pair of spacers on either Vside of said elementdeiining guide openings therewith through which said fingers extend,said spacers having surfaces normal to the direction of forces exertedon said por-` tions by a retaining ring compressed therebetween,manually actuable thumb knobs provided outside of said housing and onsaid pin for moving said pin back and forth in said slots and saidconnected fingers through said guide openings toV alternately'spreadsaid iingers and reduce the amount of spread between said ingers, saidiingers being movable into said housing into a'predetermined retractedposition, and surfaces on said fingers parallel to the Vs'urfaces onsaid spacers and engageable therewith whentsaid ngers are in saidpredetermined retracted position, Vsaid surfaces co-acting to restrainmovement of said lingers relative to said housing which might otherwisebe caused by forces exerted between said ngers and said spacers byretaining rings and the. like compressed between said work engagingportions. t t t References Cited in the fue of this patent UNITED STATESPATENTS Y 714,989 Worthington Dec. `2, 1902 1,851,126 Mikkelsen Mar. 29,1932 2,441,756 De Swart May 18, 1948 2,574,195 Sherrick NOV. 6, 1951

